\begin{tikzpicture}

\newcommand{\scale}{1}

\tikzstyle{BlockMain} =[draw=black, thick]
\tikzstyle{Block} =[draw=black, thick,  loosely dashed]
\tikzstyle{Label} =[scale=1/\scale,font=\small]

\newcommand{\MainBlockSize}{4}
\newcommand{\NeighbourBlockSize}{.45}

\draw[BlockMain] (0,0) rectangle ++(\MainBlockSize,\MainBlockSize);
% \node[Label,text width=\MainBlockSize+25,text centered]  at (\MainBlockSize/2,\MainBlockSize/2) {Current PU};

\draw[Block] (0,0) rectangle ++(-2*\NeighbourBlockSize,-2*\NeighbourBlockSize);
\node[Label]  at (-\NeighbourBlockSize,-\NeighbourBlockSize) {$A_0$};

\draw[Block] (0,0) rectangle ++(-2*\NeighbourBlockSize,2*\NeighbourBlockSize);
\node[Label]  at (-\NeighbourBlockSize,\NeighbourBlockSize) {$A_1$};

\draw[Block] (\MainBlockSize,\MainBlockSize) rectangle ++(2*\NeighbourBlockSize,2*\NeighbourBlockSize);
\node[Label]  at (\MainBlockSize + \NeighbourBlockSize,\MainBlockSize + \NeighbourBlockSize) {$B_0$};

\draw[Block] (\MainBlockSize,\MainBlockSize) rectangle ++(-2*\NeighbourBlockSize,2*\NeighbourBlockSize);
\node[Label]  at (\MainBlockSize-\NeighbourBlockSize,\MainBlockSize + \NeighbourBlockSize) {$B_1$};

\draw[Block] (0,\MainBlockSize) rectangle ++(-2*\NeighbourBlockSize,2*\NeighbourBlockSize);
\node[Label]  at (-\NeighbourBlockSize,\MainBlockSize + \NeighbourBlockSize) {$B_2$};

\draw[Block] (\MainBlockSize,0) rectangle ++(2*\NeighbourBlockSize,-2*\NeighbourBlockSize);
\node[Label]  at (\MainBlockSize + \NeighbourBlockSize,-\NeighbourBlockSize) {$T_{0}$};

\draw[Block] (\MainBlockSize/2,\MainBlockSize/2) rectangle ++(2*\NeighbourBlockSize,-2*\NeighbourBlockSize);
\node[Label]  at (\MainBlockSize/2 + \NeighbourBlockSize,\MainBlockSize/2 -\NeighbourBlockSize) {$T_{1}$};

\end{tikzpicture}